stackable carton with ventilation channels

ABSTRACT

The present invention relates to a carton including a base, and walls extending from the edges of the base, the carton characterised in that at least one wall is configured to provide a fluid conduit extending from the base of the wall to the top of the wall.

TECHNICAL FIELD

This invention relates to a storage process.

In particular, this invention relates to a storage process whichutilises packaging having particular use in the commodity businesswhereby large numbers of containers are required to be handled.

BACKGROUND ART

Discussion throughout the specification shall be made to use of thepresent invention in relation to the kiwifruit industry.

However, this should not be seen as limiting as the present inventioncan be used in many other industries, with various produce such as fruitand flowers, meats and processed foods such as cheese. It should beappreciated that many of the considerations that apply to kiwifruithowever, are also equally applicable to other products.

The kiwifruit industry in New Zealand is very large with some 2 billionpieces of fruit being exported to 65 countries. Depending upon themarket, kiwifruit is packaged in a variety of ways. A prime requirementof packaging however is that the kiwifruit arrive at its finaldestination in an unspoiled state. Fruit spoilage cause considerableloss of revenue for those in the industry.

Another desired characteristic of produce packaging is that it looksattractive and augments the brand value associated with the produce. Yetanother requirement is that the packaging is easily disposable andpreferably biodegradable.

As a solution to all of these requirements there has been developedprinted cardboard boxes designed to take a significant quantity ofkiwifruit, say in the order of between 30 and 140 kiwifruit depending onthe kiwifruit size and the box size. These boxes are made forsufficiently rigid cardboard that they can hold their size against theweight of the kiwifruit contained therein and boxes stacked on top.

Avoiding fruit spoilage can be difficult to achieve. Kiwifruit areclimacteric fruits which have a period of rapid ripening. Typicallykiwifruit are picked in an unripe state, packaged and then chilled toslow down the metabolic and ripening processes.

Effective chilling of fruit can be difficult to achieve given that thesheer volume of the packaged kiwifruit means that there is a significantmass and hence specific heat to reduce down in temperature. This iscompounded by desirability in the industry to use minimal floor spacewithin coolers by stacking the cartons so the carton sides abut eachother with stacks many layers high.

Typically, boxes are placed manually on top of a pallet. Pallets aregenerally standardised having a flat base and legs allowing four wayentry by fork lift tines.

Once the pallet has been stacked with the required number of boxes, acap in the form of treated cardboard is placed on top of the boxes andto help hold the layer of boxes in place relative to each other.

Right angled corner protectors made from rigid cardboard extend up fromthe top surface of the pallet to the caps to provide a rigid structureencasing the stack of boxes.

For example, with modular bulk boxes used in the kiwifruit industry, 100boxes can be stacked (10×10 on a pallet) to produce a stackapproximately 2 metres high, which contains around ten thousand fruit.The fruit in these boxes can take three or more days to cool down to thedesired temperature.

Similar problems occur when it is desired to introduce a controlledatmosphere to the fruit within a stack. For example, it may be desiredto introduce ethylene to hasten the ripening process just prior to thefruit being placed in a retail outlet. A stack configuration does notallow ready access of that controlled atmosphere to the fruit in thecentre of the stack, thus causing uneven ripening.

In an attempt to address this problem apertures (generally round in sizeand shape) were introduced in the ends of the cartons. In theory theseapertures allow some horizontal flow of air through the abuttingcartons.

Further, to maintain the structural integrity of the cartons theapertures are required to be small in size. Further, the natural flow ofgases having a temperature differential is in the vertical direction,which this design does not readily allow.

Another problem to address is ensuring that the boxes stay in placerelative to each other.

In an attempt to address this, some packaging has been made which lugsextending from the top surface of the boxes into recesses in the bottomsurface of the boxes placed on top. These lugs also interact withrecesses in the top cap to help secure it to the stack.

Unfortunately, this still does not provide sufficient stability to thestack of boxes.

Problems often arise during the initial phases with placing the firstrow of boxes onto the wooden pallet. It is very easy for the workers notto place the first layer in the correct positions. Consequentlysubsequent layers are also effectively out of position which can causean unstable load, or a non uniform stack which makes it difficult tohave the desired close packing between pallets.

It is an object of the present invention to address the foregoingproblems or at least to provide the public with a useful choice.

All references, including any patents or patent applications cited inthis specification are hereby incorporated by reference. No admission ismade that any reference constitutes prior art. The discussion of thereferences states what their authors assert, and the applicants reservethe right to challenge the accuracy and pertinency of the citeddocuments. It will be clearly understood that, although a number ofprior art publications are referred to herein, this reference does notconstitute an admission that any of these documents form part of thecommon general knowledge in the art, in New Zealand or in any othercountry.

It is acknowledged that the term ‘comprise’ may, under varyingjurisdictions, be attributed with either an exclusive or an inclusivemeaning. For the purpose of this specification, and unless otherwisenoted, the term ‘comprise’ shall have an inclusive meaning—i.e. that itwill be taken to mean an inclusion of not only the listed components itdirectly references, but also other non-specified components orelements. This rationale will also be used when the term ‘comprised’ or‘comprising’ is used in relation to one or more steps in a method orprocess.

Further aspects and advantages of the present invention will becomeapparent from the ensuing description which is given by way of exampleonly.

DISCLOSURE OF INVENTION

According to one aspect of the present invention, there is provided acarton including

a base, and

walls extending from the edges of the base,

the carton characterised in that

at least one wall is configured to provide a fluid conduit extendingfrom the base of the side wall to the top of the wall.

According to one aspect of the present invention, there is provided apallet including

a support platform for placing cartons thereon,

characterised in that

the support platform includes recesses designed to cooperate withprotrusions depending from the base of the cartons.

According to another aspect of the present invention, there is provideda carton including

a base

walls extending upwards from the edges of the base,

characterised in that

the carton includes protrusions depending downwards from the base andrecesses positioned on an upper part of the carton wherein the recessesare designed to cooperate with the protrusions.

According to yet another aspect of the present invention there isproviding a packaging system including a pallet as described above, incombination with cartons as described above.

The term fluid conduit should be understood to be any passageway thatfluid (most likely a gas) can travel along. For ease of referencethroughout the specification, the fluid conduit will be referred to as aventilation channel, although it should be appreciated that the conduitcan be used for a number of uses other than just purely ventilation—forexample, cabling.

In preferred embodiments, the carton will be of similar size and shapeto that already used in industry but with the addition of the fluidconduits or ventilation channels.

For example, if a carton in accordance with the present invention was tobe used in the kiwifruit industry, then it is envisaged that it would bemade from a paper material such as cardboard.

Preferably, the carton is made from corrugated cardboard such as thatdescribed in the applicant's corresponding patent application numberNZ571716.

It should be appreciated however that the choice of material should notbe seen as limiting as the present invention can be applied to cartonsmade from other materials for example, plastics material.

The preferred use of the present invention is to provide effectiveventilation channels when the cartons are used in a stackedconfiguration. Therefore the structure of the cartons is preferably suchthat they can be readily stacked on top of each other.

Therefore in preferred embodiments the entrance to the channel at thebase of the side wall of a first carton corresponds approximately to theexit of the channel at the top of the side wall of a second cartonpositioned directly underneath the first carton.

This is most readily achieved if on a particular wall the entrance andexit of the channel are substantially immediately above and below eachother.

In some embodiments, the conduit between the exits and entrances is inthe form of a tortuous path providing a maximum length of travel offluid passing along the conduit before exiting same. This gives maximumcontact of the fluid with the box and the contents therein.

In preferred embodiments however, the path between exit and entrance issubstantially straight. Not only is this the simplest constructionincorporating the present invention, but also one which ensures that theintegrity of the cartons is maintained.

This latter point is very important when considering that the preferreduse of the invention involves cartons having to support considerableweight.

It is envisaged that there may be any number of channels in the sidewalls of the carton depending upon the intended use of the carton.Consideration however must be given to maintaining structural integrityof the carton.

In preferred embodiments, the channels are in the form of well definedindents having dimensions of 20 mm wide and 10 mm deep. As in preferredembodiments the cardboard is 10 mm thick.

For reasons of strength and aesthetics, the cross section of thesechannels may be similar to that of the lugs/recesses which typicallyextend upwards from kiwifruit cartons.

In this embodiment, it is envisaged that the channel may be formed bymerely stamping out or removing by other means a rectangular strip fromthe carton blank prior to assembly.

In similar embodiments, the channels may be formed as a consequence ofprojections extending from the sideways from the carton.

It should be appreciated that in normal stacking configurations, theside walls of the carton abut closely to each other. If there areprojections which extend side ways out from the side walls (or base ortop), then when boxes are placed close together, the projections wouldcause a gap between the main body of the cartons. This in effect canprovide a ventilation channel between cartons.

It is envisaged that this form of the invention could be achieved byhaving an overhang of for example, approximately 2 mm from the top,bottom and/or end of the carton.

The protrusion can be achieved by a variety of ways. In one embodiment,the protrusion may result from attaching an additional piece of materialto part of the carton.

In another embodiment, the protrusion may result from the design of thecarton blank and the way that it is folded. In one particularembodiment, the folding of the carton blank may also enable keying in ofthe top surface of the carton to the side walls in the form of a lockingflap, obviating the need to glue the cartons.

It is envisaged that the channels will be symmetrically positioned onthe carton. This is not only for aesthetics, but also to maximise thechannel size.

For example, with symmetrically positioned channels, the boxes may beplaced together so that the protrusions and/or channels on each cartonoppose each other, thereby effectively creating a ventilation channelhaving double the width of that provided by a single carton abutting aside panel without protrusions or channels.

Care needs to be taken that the gap provided by the channels does notsignificantly increase the floor/pallet space taken up by the cartons.Therefore, in some embodiments, it may be that the cartons have higherside panels than conventional cartons to provide the extra volumerequired for the same floor space. For example, to allow for thechannels, the base of each carton may have a reduced cross-sectionalarea available to the produce requiring a greater carton height toprovide the same volume.

In preferred embodiments of the present invention, the cartons are madein accordance with an interlocking system. For example, the cartons mayhave lugs depending downwards or extending upwards from the cartonswhich fit into complementary indents on the cartons above and below.This system can ensure that the ventilation channels are alignedallowing maximum airflow through the carton stack.

In preferred embodiments, the present invention is used in combinationwith a pallet which likewise has apertures that can correspond to thepositioning of ventilation channels of the cartons placed on top of thepallet.

This process is aided if the pallet has locating means that the cartonscan lock into. For example, the pallet may have apertures configured sothat downwardly depending lugs in the cartons can fit into them. Oncethe cartons are positioned on the pallet in this way, then there can bea continuous flow through of air from underneath the pallet and upthrough the cartons.

With protrusions depending downwards from the carton, the protrusionseffectively will be acting as feet to the cartons, when the cartons areplaced on a non-recessed surface. This situation is most likely to occurin a retail situation where a single layer of boxes will be used fordisplay purposes.

It should be appreciated that the cartons would only be used in astacked format when the lower layer of cartons have recesses that canreceive the protrusions. This is because to take the full weight of thestack, the base of the box is also required to provide that support.

In some embodiments of the present invention, there will still beprotrusions extending upwards from the cartons which can engage withrecesses in the base of cartons stacked on top.

It is thought by having lugs extending upwards and depending downwardsfrom the cartons, that torsional stresses on the sides of the cartoncould be reduced when interlocked.

Another reason to have the upward projections is to enable the top layerof stacked cartons to cooperate with recesses in a cap which ispreferably used with a packaging system in accordance with the presentinvention.

It is also envisaged that the packaging system would use cornerprotectors which will extend from the pallet base to the cap.

In preferred embodiments the corner protectors are made in accordancewith the process as described in New Zealand Patent Application No.569462 as this process provides an extremely strong component.

Also, in preferred embodiments the cap, the box and corner boards aremade from a corrugated paper board such as that described in New ZealandPatent Application No. 571716. Again, this is preferred as this providesan extremely strong product, but should not be seen as limiting.

It should be appreciated that one aspect of the present inventionincludes the use of downwardly depending lugs, but without theventilation channels. This configuration is still useful in providing asecure and stable stack for products which do not require as muchventilation as say the kiwifruit industry. For example, ventilationchannels will not necessarily be required to the same degree for producesuch as apples or non-organic products.

In one embodiment of the present invention there is provided a cartonwith at least one upwardly extending lug having at least one recessconfigured such that a portion of a lid of the carton can be securedtherein.

Such a feature enables a lid to be secured without the need foradditional securing means such as tape and the like. Further, noexcessive folding will be required as merely a recess is used. Further,the dual use of lugs as a source of stability and securing for the lidmakes for efficient and effective design.

According to one aspect of the present invention there is provided acarton having at least one lug upwardly extending from the end of thecarton wherein the carton also includes a complimentary recess toreceive a lug from a similar carton placed thereunder.

This configuration gives considerable stability—particularly if the lugis comparatively large with respect to the end wall.

While reference throughout the specification has been made mainly to theuse of the present invention with regard to the kiwifruit industry, itshould be appreciated that the invention can apply to other packagedgoods.

For example, the present invention may apply to fruit having a smallersize than kiwifruit, for example grapes and blueberries or, the presentinvention could be applied to products having an amorphous shape, suchas cooling cheese, powder and the like.

With these particular products, it is possible that the product could beprone to fall, or ooze out of the larger apertures or channels requiredto gain the appropriate cooling.

According to another aspect of the present invention there is provided acarton having a number of apertures therein, the carton also including agas permeable laminate covering said apertures.

According to a further aspect of the present invention there is provideda carton as previously described

characterised in that

the carton includes a gas permeable laminate positioned over at leastone of the fluid conduits provided by the carton.

In preferred embodiments, the laminate has the properties of being ableto retain the products within the carton, while allowing the passage offluid (most likely gas) into and out of the carton.

In some embodiments the laminate may be made from a gas permeablemembrane having no readily visible apertures therein, such as that usedin the meat packaging industry. This membrane may in some embodiments beselective, for example permitting a one way passage of oxygen and/orethylene.

However, it is envisaged that to obtain the gas flow required, themembrane is more likely to be the form of a mesh with open apertures.The size of the apertures in likely to be such that the product withinthe carton will be retained without passing through the mesh and out thecarton apertures.

It is envisaged that the present invention could be used in concert withcorrugated cardboard such as that described in the applicant'scorresponding New Zealand Patent Application No. 571716.

For example, a standard carton blank may be made having the variousapertures and channels punched therefrom. The carton blank can then beconveyed to a laminating station where the laminate is adhered onto thecardboard.

The final shape of the carton blank and laminate can then be cut fromthe cardboard, prior to the carton being assembled from the cartonblank.

The present invention has a number of advantages over the prior art.

Firstly, there is provided an easy means by which large volumes ofproduce (and other products) can be readily cooled by the provision ofventilation channels.

Likewise, there is provided a means by which a gas can be readilydelivered (or removed) from the produce as required—for exampleethylene.

Further, it can be seen that an aspect of the present invention providesa simple but elegant solution to the problem of stack stability.

By having recesses on a pallet that can interact with carton lugs, theinitial layer of cartons will be located exactly the right positions onthe pallet. As subsequent layers have to lock into the layers below,then the whole stack of pallets will be perfectly aligned andcentralised with the pallet underneath.

With embodiments that have upwardly extending lugs as well, the top capto the carton stack will also be secured.

It can be seen that a top cap, corner protectors and interlocking palletwith the cartons can form a very rigid structure.

Further, if the components are made with corrugated paper board made inaccordance with the applicants proprietary processes, there is provideda strong lightweight packaging system which is also ecologicallyfriendly.

The present invention can be formed using simple technology such as thatalready developed by the applicant.

The choice of using interlocking pallet, cartons and top cap to providealigned ventilation channels provides a secure packaging system, as acombination of features provides additional strength limiting productdestruction due to crushing.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from thefollowing description which is given by way of example only and withreference to the accompanying drawings in which:

FIG. 1 is a perspective view of a carton in accordance with oneembodiment of the present invention, and

FIG. 2 illustrates the interaction of the carton in accordance with apallet made in accordance with an embodiment of the present invention,and

FIG. 3 illustrates a packaging system in accordance with one embodimentof the present invention, and

FIG. 4 illustrates virtual conduits in accordance with one aspect of thepresent invention, and

FIG. 5 illustrates an alternative carton in accordance with one aspectof the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

FIG. 1 illustrates a carton generally indicated by arrow (1) made inaccordance with one embodiment of the present invention.

The carton (1) is made from a high strength corrugated paperboard suchas that described in New Zealand Patent Application No. 571716.

The carton (1) has end panels (2 and 3) extending upwards from a base(not clearly shown). Side panels (4 and 5) also extend upwards from thebase.

In the embodiment shown, top edges (6 and 7) fold over from the sidepanels (4 and 5 respectively) and interlock with the end panels (2 and3) to form a rigid box shaped structure.

In the embodiment illustrated in FIG. 1, there are a number ofdownwardly depending lugs (8) from the side panels (4 and 5). It shouldbe appreciated that the lugs may depend from the ends (2 and 3) inaddition to or instead of depending from the sides (4 and 5).

In this embodiment, the lugs (8) are situated close to the four outercorners of the carton to effectively act as supporting feet when placedon a flat surface.

Directly above lugs (8) are recesses (9) which are of a complementarysize and shape to the lugs (8). Thus, when a carton is placed on top ofanother carton (as illustrated in FIG. 3) the lugs (8) fit snugly intothe recesses (9). In this position, the base of the carton (1) is alsosupported by the top edges (6 and 7).

Extending upwardly from the side panels (3 and 4) are lugs (10) havingsimilar configurations to the lugs (8). Likewise, directly beneath thelugs (10) are recesses (11) having similar configurations to therecesses (9). Thus, the lugs (10) cooperate with the recesses (11) whenthe cartons (1) are stacked on top of each other.

Ventilation channels in the form of cut-outs (20) have been formed inthe sides (4 and 5) of the carton (1). The channels (20) are merelyrectangular slots which have been cut in between the lugs and recesseson the sides (4 and 5) of the carton (1).

An alternate form of ventilation channel generally indicated by arrow(21) is formed at the ends (2 and 3) of the carton (1). It can be seenat the ends (2 and 3) of the carton (1) that there are apertures (22)which are in a form found in typical produce cartons. Extending outwardsat the top of the end panels (2 and 3) are protrusions (24). Theprotrusions (24) extend only in the order of around 2 mm out from theflat surface of the ends (2 and 3).

Thus it can be seen that when the cartons (1) abut each other, a 4 mmgap is formed between the side panels (2 and 3) as a consequence of theprotrusions (24). This ventilation channel (21) allows air flowingbetween the cartons to also enter the apertures (22).

When the panels (3 and 4) abut each other, then there is provided an 4mm wide channel which allows vertical and horizontal air flow.

It is envisaged that all of the lugs, channels, apertures and recessesshown in the carton (1) will be stamped from a flat piece of corrugatedpaper board. This could be stamped or rotary cut instead.

FIG. 2 illustrates a pallet made in accordance with one embodiment ofthe present invention. The image is transparent to aid the explanation.

The pallet (12) has a number of recesses (13) that cooperate with thelugs (8) on the carton (1).

It can be seen that when the carton (1) is placed on the pallet (12),the base (14) of the carton (1) sits flat on the upper surface (15) ofthe pallet (12). Therefore, the full weight of the stack of pallets innot on the lugs (8) but is borne by the upper edges (6 and 7), sidepanels (2 and 3) and the base (14) and the pallet surface (15).

The pallet (12) also has a number of larger apertures (25) whichcorrespond to the ventilation channels (20) on the cartons (1) when thecartons are placed in position.

In some embodiments (although not shown), there may also be providedequivalent slots that correspond with the ventilation channel (21)formed by the protrusions (24).

FIG. 3 illustrates a packaging system in accordance with one embodimentof the present invention. The packaging system consists of a palletgenerally indicated by arrow (12) having nine feet (16) allowing a fourway entry system for forklifts. Cartons generally indicated by arrow (1)are stacked so that the respective lugs (8 and 10) interact respectivelywith recesses (9 and 11) to form an overall locking structure.

A top cap (17) is placed on the top of the stack of cartons (1). The topcap (17) is also made from corrugated paperboard as previously describedand has a number of recesses (not clearly shown) punched out therefrom.which correspond to the lugs (10) on the cartons (1).

Also not clearly shown are apertures which correspond to the ventilationchannels (20) between the cartons (1) and the apertures (25) in thepallet (12).

Corner pieces (18) also made from corrugated paperboard extend from thebase or the pallet (12) to the top cap (17). It can be seen that intotal the structure illustrated by the packaging system is very robustgiven that it interlocks in multiple directions.

To further assist the integrity of the packaging system, straps (notshown) may be wrapped around the corner protectors and/or pallet and topcap to hold the whole structure into position.

FIG. 4 illustrates some fluid conduits (22) that occur between stackedcartons (1).

FIG. 5 illustrates an alternate aspect of the present invention with acarton (30) which could be useful for produce such as apples.

The carton (30) is made from the same material as the carton (1), namelyhigh strength corrugated paper board such as that described in NewZealand Patent Application No. 571716.

The carton (30) has a different lug configuration to that in carton (1).Namely, there is provided large lugs (31) and (32) which extend upwardlyfrom the end walls (33) and (34) respectively of the carton (30).

Opposing the lugs (31) and (32) are recesses (35) (one recess notclearly shown). Thus, when cartons of the configuration shown arestacked on top of each other the lug (32) fits into the recess (35)providing stability to the stack of cartons.

The lugs (31) and (32) have recesses (36) formed by an undercut. Theconfiguration recesses (36) allow a portion of the lid (37) and (38) ofthe carton (30) to tuck therein. Thus, the lugs (31) and (32) can act tosecure the lid portions (37) and (38) of the carton (30). This obviatesthe need for additional tape, glue or securing means. This also enablesthe carton (30) to be readily opened when required.

Aspects of the present invention have been described by way of exampleonly and it should be appreciated that modifications and additions maybe made thereto without departing from the scope of the appended claims.

1. A paper material carton including: a quadrilateral base; and fourside walls extending out from the edges of the base, wherein at leastone side wall is configured to solely provide a fluid conduit extendingfrom the base of the side wall to the top of the side wall(s) whereinthe walls define a quadrilateral interior for the carton which has nointernally projecting surfaces.
 2. A paper material carton including: aquadrilateral base; and four side walls extending out from the edges ofthe base, wherein at least one side wall is configured to provide afluid conduit extending from the base of the side wall to the top of theside wall(s) wherein the fluid conduit is formed by removing arectangular strip from the carton blank prior to assembly.
 3. The papermaterial carton of claim 1 wherein the fluid conduit is a ventilationchannel.
 4. The paper material carton of claim 3 wherein, when cartonsare stacked one on top of another the entrance to the channel at thebase of the side wall of a first carton corresponds at leastapproximately to the exit of the channel at the top of the side wall ofa second carton positioned directly underneath the first carton.
 5. Thepaper material carton of claim 4 wherein the path between exit andentrance of the channels is substantially straight.
 6. The papermaterial carton of claim 1 further comprising projections which extendsideways from the carton.
 7. The paper material carton of claim 4wherein the channels are symmetrically positioned on the carton.
 8. Thepaper material carton of claim 7 wherein the channels and projectionsare positioned such that the projections and/or channels on each cartonoppose each other, thereby effectively creating a ventilation channelhaving double the width of that provided by a single carton abutting aside panel without protrusions or channels.
 9. The paper material cartonof claim 1 further comprising an interlocking system.
 10. The papermaterial carton of claim 1 further comprising a gas permeable laminatepositioned over at least one of the fluid conduits provided by thecartons.
 11. The paper material carton of claim 1 further comprisingapertures with a gas permeable laminate covering some of the apertures.12. The paper material carton of claim 1 further comprising: a base; andwalls extending upwards from the edges of the base, wherein the cartonincludes protrusions depending downwards from the base and recessespositioned on an upper part of the carton wherein the recesses aredesigned to cooperate with the protrusions.
 13. The paper materialcarton of claim 5 further comprising protrusions extending upwards whichcan engage with recesses in the base of similar cartons stacked on top.14. The paper material carton of claim 12 wherein the protrusionsinclude a recess that can receive a portion of a lid section of thecarton in order to secure the lid section with respect to theprotrusion.
 15. The paper material of claim 1 further comprising atleast one upwardly extending lug having at least one recess configuredsuch that a portion of a lid of the carton can be secured therein.
 16. Apaper material carton which includes: a quadrilateral base; and fourside walls extending out from the edges of the base, wherein at leastone side wall is configured to provide a fluid conduit extending fromthe base of the side wall to the top of the side wall(s) wherein thewalls define a quadrilateral interior for the carton which has nointernally projecting surfaces wherein the at least two opposed sidewalls have at least one lug upwardly extending from the carton andwherein the carton also includes a complimentary recess on the said twoopposed side walls which can receive a lug from a similar carton placedthereunder.
 17. The paper material carton of claim 16 wherein theupwardly extending lugs are on the end walls of the carton as are thecomplimentary recesses which receive said lugs.
 18. The stack of cartonsof claim 16 wherein the stack is located on a pallet.
 19. (canceled)20-28. (canceled)